Buying guide · Filters & flow
Best External Aquarium Filters
Compare external aquarium canisters by installed-flow context, cabinet space, media access and exact replacement compatibility, including Fluval and JBL options.
The quick choice
Choose for the installation
Look at cabinet access, media space and appropriate circulation together. A larger canister is useful only when the aquarium and maintenance space justify it.
Compare the practical differences
| Model | Maker’s aquarium range | Stated flow | Installation focus |
|---|---|---|---|
| AllPondSolutions EF-150 | Up to 150 L | 400 L/h pump | Compact format; confirm permitted positioning in its manual |
| Fluval 207 | 60–220 L | 780 L/h pump; 460 L/h circulation (120 V / 60 Hz reference) | 19 × 18 × 42 cm body plus service clearance |
| Fluval 307 | 90–330 L | 1150 L/h pump; 780 L/h circulation (120 V / 60 Hz reference) | 24 × 18 × 42 cm body; wider than the 207 |
| JBL CristalProfi e702 | 60–200 L | 700 L/h maximum pump | 12/16 mm hoses; check full connection envelope |
Pump and circulation figures are not interchangeable. Use the manufacturer ranges alongside the actual fish load, flow requirements and maintenance access.
The shortlist
External canisters to compare
Keeping the main filter outside the tank
AllPondSolutions EF-150 external filter
An external canister with supplied hose, media and a spray bar. It frees space inside the aquarium, while adding hoses, connections and a canister that need accessible positions.
- 400 L/h rated output
- Up to 150 L maker rating
- Hose, media and spray bar included
A setup with room outside the aquarium for the filter and a safe, accessible hose route.
- Check the manual’s installation-height and hose requirements.
- Inspect connections and seals; external filtration adds potential leak points.
Accessible baskets in a narrower cabinet
Fluval 207 external canister filter
A canister with removable media baskets, a primer and AquaStop control. Its published pump output and filter-circulation figures describe different operating conditions.
- 19 × 18 × 42 cm body
- 1.8 L published basket volume
- 10 W at 230–240 V / 50 Hz
A setup that suits the maker’s 60–220 L range, with room for the body, hoses and service movement.
- Allow extra height for hoses and removal; 42 cm is not the whole service envelope.
- Flow regulation has a manual-defined limit; do not close the operating valve beyond it.
- The current web flow table labels its figures 120 V / 60 Hz; check the data for your electrical variant.
A larger basket arrangement
Fluval 307 external canister filter
A larger 07-series option with the same broad maintenance format as the 207. More media space and higher flow make it a different installation choice, not an automatic upgrade for a small tank.
- 24 × 18 × 42 cm body
- 3.1 L published basket volume
- 15 W at 230–240 V / 50 Hz
An aquarium whose circulation and waste requirements justify the larger unit and whose cabinet has the required width.
- Wider than the 207 despite the same stated body height.
- Do not use 207 foam packs or assume a shared family name means all parts interchange.
- Published web flow references are labelled 120 V / 60 Hz; check the data for your electrical variant.
A separate prefilter arrangement
JBL CristalProfi e702 greenline external filter
A canister with accessible prefilter inserts, a priming button and rotating hose connections. Its maximum pump figure is not the flow guaranteed after hoses and media are installed.
- 700 L/h maximum pump output
- 12/16 mm hose connections
- Approximately 35 cm nominal body height
An aquarium within the maker’s 60–200 L application range with room for the full hose-connection and removal envelope.
- Check the UK-plug version and the full installation drawing before ordering.
- Match e702-specific rotor and foam variants rather than choosing by the e-series name alone.
What this shortlist is designed to help you choose
An external aquarium filter moves the main media container outside the tank. That frees internal space and can provide useful media capacity, but introduces hoses, valves and seals that need attention. We compare four canisters for different installation needs: the compact AllPondSolutions EF-150, Fluval 207, wider Fluval 307 and JBL CristalProfi e702 greenline. Our recommendations follow published specifications and maintenance arrangements.
Start with the aquarium rather than the product’s largest litre label. Establish usable water volume, the fish’s circulation needs and the likely feeding load. A canister is not an answer to unsuitable stocking, and a new canister still needs to mature. If you cannot provide a safe, accessible location and a sensible hose route, an internal filter may be the more workable choice.
The differences that matter after installation
AllPondSolutions EF-150: a compact canister option with a 400 L/h pump specification and an up-to-150 L maker label. Included hoses, media and spray bar make it a useful option to investigate for a smaller installation, but do not infer an operating height from the litre rating. Read the actual installation instructions before deciding where it will sit. Check how the lid is released and whether the supplied hoses reach without stretching or sharp bends.
Fluval 207: suits consideration where its 19 × 18 × 42 cm body can fit with additional hose and servicing clearance. Fluval’s web table lists 780 L/h pump output and 460 L/h filter circulation as 120 V / 60 Hz references. Check the flow data for the electrical variant being supplied. Those are two different stated measures, not contradictory labels and not a promise of the flow in every tank. Its 1.8 L basket volume is another useful comparison point, although media arrangement and established biology matter more than volume alone.
Fluval 307: has a 24 × 18 × 42 cm body and 3.1 L basket volume. Its published pump output of 1150 L/h and circulation figure of 780 L/h are labelled 120 V / 60 Hz references in the manufacturer’s web table. Compare like-for-like electrical variants and measurement conditions before using those numbers to judge a UK installation. The shared 42 cm body height does not mean a cabinet that takes a 207 also accepts a 307. Check the wider body, valve assembly and space to lift the complete unit safely.
JBL CristalProfi e702 greenline: offers a prefilter arrangement, priming button and rotating hose connections. JBL specifies 700 L/h maximum pump output, 12/16 mm hose connections and an application range of 60–200 L. Its nominal body height is around 35 cm, but fittings and removal space extend the working envelope. Check the exact UK-plug listing and current installation drawing; do not use a bare body measurement as your cabinet’s minimum internal height.
Measure a service envelope, not just a rectangle
Open the cabinet door fully and measure its narrowest opening. Allow room for the hoses to curve without kinking, valve movement, power-cable routing and the path out of the cabinet. A shelf above the motor head may prevent valve removal even when the body fits below it. Keep connections visible enough to inspect and make sure the unit sits on a stable surface in the position required by its manual.
The filter’s position relative to the aquarium affects priming and operation. Use the maker’s permitted height relationship; a model designed to sit below the water line should not be relocated to a shelf above it because the hoses happen to reach. Avoid leaving a long spare loop that traps air or creates an awkward route. Cut or assemble tubing only as the instructions permit.
Plan where you will carry the canister for servicing and how you will isolate it. Household access matters: an installation behind an immovable cabinet is difficult to inspect for seepage or reconnect properly. Follow electrical isolation instructions before maintenance, maintain dry connections and recheck joints after reassembly. Never operate a canister dry in an attempt to prime it.
Why the biggest flow number is not the full comparison
Maximum pump output is usually measured under conditions different from a filled, installed filter. Hoses, lift, elbows, media and debris affect delivery. The source-qualified Fluval reference figures above help demonstrate the distinction: dividing the 207’s 780 L/h pump figure by a tank volume gives a different result from using its 460 L/h circulation figure. Neither calculation measures the current movement behind your aquarium’s wood and plants.
Look for a return that distributes movement across the aquarium. A spray bar can spread the outlet, whereas a narrow nozzle may produce a stronger local jet. Fish behaviour, surface movement and areas where waste settles tell you about distribution. Read how to choose for actual volume and fish before treating a turnover number as a buying rule.
On Fluval 07 filters, the AquaStop operating instructions limit how far the regulating lever may be raised while running: no higher than halfway. That describes lever travel, not a calibrated 50% water-flow setting. Do not use a locking mechanism as a regulator, throttle an intake indiscriminately or force a larger filter into service with nearly closed valves.
What to budget for beyond the canister
Compare the supplied media with the long-term replacements. Reusable foam can be cleaned; disposable fine media and chemical adsorbers have different maintenance needs. Preserve established biological material during changes and avoid treating a full replacement pack as an instruction to discard every stage together. See when to replace filter media for a practical replacement checklist.
Compatibility follows the exact model and part reference. The Fluval 206/207 foam pack is not the 306/307 pack. A 12/16 mm hose description gives two dimensions, not permission to fit any similarly named valve assembly. Rotors, seals and hose adapters may be specific even within one family. Save the model number and parts diagram before the packaging goes away.
Running cost is another concrete comparison: Fluval lists 10 W for the 207 and 15 W for the 307 on the stated UK electrical supply. Use your own tariff in our electricity calculator; these inputs do not establish which filter is quieter or better for your fish. The best purchase balances appropriate capacity with access you can maintain for the life of the aquarium.
For installation and service, use priming an external filter, canister media order and seal, hose and leak checks. These tasks depend on the exact model and its water path, not just the maker’s upper litre label.
Common questions
Is an external filter better than an internal filter?
An external canister can provide media space outside the aquarium, but requires hoses, seals and cabinet access. An internal filter may be simpler to accommodate and service. Choose around the installation and livestock rather than assuming one format always performs better.
Can I choose a canister using the maximum tank rating?
Use that rating as a starting screen, then examine actual volume, waste load, media capacity and return control. A maker’s upper litre label does not account for every fish, feeding routine or arrangement of rocks and plants.
How much space should I leave above a canister?
There is no universal clearance. Measure the exact body, hose assembly and path needed to release valves and remove the head. Follow the installation drawing and check that the complete filter can pass through the cabinet opening.
Why are pump output and filter circulation different?
They describe different measurement conditions. Installed media and the hydraulic path reduce delivery compared with a bare pump figure. Fluval publishes separate figures for its 07 series; your aquarium’s own hoses and maintenance condition can change the result further.
Can I swap a mature internal filter straight for a new canister?
Do not assume the new media is mature. Plan a transition that preserves established filtration and monitor ammonia and nitrite while the new filter establishes. Matching litres-per-hour figures does not transfer the biological population to a new filter.
Are Fluval 207 and 307 replacement foams interchangeable?
Choose the exact pack specified for your model. Fluval lists a 206/207 pack separately from the 306/307 variant. A shared filter family and similar appearance are not enough to establish that a replacement has the correct dimensions and water path.
Sources and further reading
- OATA: filtration and freshwater water quality
- AllPondSolutions EF-150: supplied equipment and specification
- Fluval 207: dimensions, power and circulation
- Fluval 307: dimensions, basket volume and circulation
- Fluval 07 series: installation, priming and flow control
- JBL e702: model specification
- JBL CristalProfi e manual: installation and servicing